Retract GrTexture.h a bit

This began as cleaning up SkSpecialImage.h & spiraled out of control from there.

Change-Id: I9a570ecd2a7af9ee724ebfebe4e9185748f38bbc
Reviewed-on: https://skia-review.googlesource.com/19290
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
diff --git a/tests/ClipStackTest.cpp b/tests/ClipStackTest.cpp
index 1cb644a..af57f9e 100644
--- a/tests/ClipStackTest.cpp
+++ b/tests/ClipStackTest.cpp
@@ -17,6 +17,7 @@
 #include "GrReducedClip.h"
 #include "GrResourceCache.h"
 #include "GrSurfaceProxyPriv.h"
+#include "GrTexture.h"
 #include "GrTextureProxy.h"
 typedef GrReducedClip::ElementList ElementList;
 typedef GrReducedClip::InitialState InitialState;